package com.alibaba.work.faas.util;

import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import org.apache.commons.codec.binary.Base64;

import com.aliyun.tea.utils.StringUtils;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class DESUtil {
    private static final String DES = "DES";

    // 加密方法
    public static String encrypt(String data, String key) {
        if (StringUtils.isEmpty(data) || StringUtils.isEmpty(key)) {
            log.info("data or key is null,data:{},key:{}", data, key);
            return null;
        }
        try {
            byte[] bt = encrypt(data.getBytes(), key.getBytes());
            String strs = Base64.encodeBase64String(bt);
            return strs;
        } catch (Exception e) {
            log.error("encrypt error", e);
            return null;
        }

    }

    public static String decrypt(String data, String key) {
        if (StringUtils.isEmpty(data) || StringUtils.isEmpty(key)) {
            log.info("data or key is null,data:{},key:{}", data, key);
            return null;
        }
        try {
            byte[] dataNew = Base64.decodeBase64(data);
            byte[] bt = decrypt(dataNew, key.getBytes());
            return new String(bt);
        } catch (Exception ex) {
            log.error("decrypt error", ex);
            ex.printStackTrace();
        }
        return null;

    }

    public static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始秘钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey secretKey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成加密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, sr);

        return cipher.doFinal(data);
    }

    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成解密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

}
